Electricity Merit Badge DC Direct Current Staff Direct

Electricity Merit Badge DC Direct Current Staff

Direct Current Glass of Water has Force called pressure Carbon Rod Gel Insulator Zinc Casing Charged Battery 1. 5 volts 3 m 3 m Flashlight + + + --- - - Empty Glass Has no Force - ------ - Switch - Current Flow Electrons Battery works from a chemical reaction between the carbon rod and zinc case + + + --+ + - -+-- Dis-Charged Battery No Voltage is the quantity of electrical force Measured in Volts Current is the flow of ___electrons___ Measured in Amps DC Stand for Direct Current DC is current flowing in one direction

Direct Current Pass out Typical Battery Rating - How Long will they Last Flashlight This is like 4 different Size cups of water 1. 5 volts 0. 1 Amp 2 m 5 m 1. 5 volts 4 Amps Hours AA Cell C Cell D Cell 2 Amps Hours AAA Cell 1. 5 volts . 5 Amps Hours If a flashlight pulls. 1 Amp, how long will each battery last? Time = Amp Hours / Load in Amps D cell = Amp Hours = _______ hours Amps C cell = Amp Hours = _______ hours Amps AA cell = Amp Hours = ________ hours Amps AAA cell = Amp Hours = ________ hours Amps . 2 Amps Hours Pg 18

Direct Current Battery Types How Long will they Last Flashlight 1. 5 volts 0. 1 Amp 1 m 6 m 1. 5 volts 4 Amps Hours AA Cell C Cell D Cell 2 Amps Hours AAA Cell 1. 5 volts . 5 Amps Hours If a flashlight pulls. 1 Amp, how long will each battery last? Time = Amp Hours / Load in Amps D cell = Amp Hours = __4___ = __40__ hours Amps. 1 C cell = Amp Hours = __2___ = __20___ hours Amps. 1 AA cell = Amp Hours = ___. 5__ = ___5____ hours Amps. 1 AAA cell = Amp Hours = __. 2___ = ___2____ hours Amps. 1 . 2 Amps Hours Pg 19

Direct Current Cost of Batteries for the Same Output D Cell $ 1. 50 4 Amps Hours Same 2 - C Cell as 2 x$1. 10 = $2. 20 as = 2 2 Amps Hours 8 – AA Cell 8 x$. 65 = $5. 20 . 5 = . 5 . 5 8 x. 5 = 4 Amps Hours . 5 . 5 Amps Hours Same as = 2 m 8 m 20 – AAA Cell 20 x $. 45 = $ 9. 00 20 X. 2 = 4 Amps Hours The more Batteries The more waste Pg 20

Many Battery Types • Zinc-carbon battery - Also known as a standard carbon battery, zinc-carbon chemistry is used in all inexpensive AA, C and D dry-cell batteries. The electrodes are zinc and carbon, with an acidic paste between them that serves as the electrolyte. • Alkaline battery - Used in common Duracell and Energizer batteries, the electrodes are zinc and manganese-oxide, with an alkaline electrolyte. • Lithium photo battery - Lithium, lithium-iodide and lead-iodide are used in cameras because of their ability to supply power surges • Lead-acid battery - Used in automobiles, the electrodes are made of lead and leadoxide with a strong acidic electrolyte (rechargeable). • Nickel-cadmium battery - The electrodes are nickel-hydroxide and cadmium, with potassium-hydroxide as the electrolyte (rechargeable). • Nickel-metal hydride battery - This battery is rapidly replacing nickel-cadmium because it does not suffer from the memory effect that nickel-cadmiums do (rechargeable). • Lithium-ion battery - With a very good power-to-weight ratio, this is often found in high-end laptop and cell phones (rechargeable). • Zinc-air battery - This battery is lightweight and rechargeable. • Zinc-mercury oxide battery - This is often used in hearing-aids. • Silver-zinc battery - This is used in aeronautical applications because the power-toweight ratio is good. • Metal-chloride battery - This is used in electric vehicles 1 m 9 m Pg 21

Flashlight Diagram Slide Switch Tension Spring (-) Battery Contact Battery Cells Slide Switch Added Potentiometer Changes Light Level Battery 2 m 11 m Battery Cells Pg 22

Car DC Electrical System Name four electrical items in a car 1 m 12 m

Car DC Electrical System 1 m 12 m

Build an Electrical Switch 1 m 13 m

Build an Electrical Switch 5 m 18 m

Direct Current Test Box Draw 4 different wiring test circuits, then pass out boxes. Switch Light 1 m 19 m Power + 12 Fuse Buzzer

Direct Current Test Box Draw Circuit to Switch Buzzer On / Off - Instructor draws this one first Switch Light 1 m 20 m Power + 12 Fuse Buzzer Instructor ____

Direct Current Test Box Draw Circuit to Switch Buzzer On / Off - Instructor draws this one first Switch Buzzer On Light 1 m 21 m Power + 12 Fuse Buzzer Instructor ____

Direct Current Test Box Draw Circuit to Switch Light On / Off Switch Light 1 m 22 m Power + 12 Fuse Buzzer Instructor ____

Direct Current Test Box Draw Circuit to Switch Light On / Off Switch Power + 12 Fuse Light On Light 1 m 23 m Buzzer Instructor ____

Direct Current Draw Circuit to Turn Buzzer on in one Direction and Light in other Direction Switch Light 1 m 24 m Power + 12 Fuse Buzzer Instructor ____

Direct Current Draw Circuit to Turn Buzzer on in one Direction and Light in other Direction Switch Light On Light 1 m 25 m Buzzer On Fuse Power + 12 Buzzer Instructor ____

Two Switches Control One Light Switch Two different Light Switches Control one Light Battery Switch Light 1 m 26 m

Draw a Circuit with Two Switch External Switch and On-board Switch When complete dismantle switch box and put all components back into its box. Switch Light On Turn Light on 1 m 27 m Power + 12 Fuse Buzzer On Light Buzzer Pass out boxes, connect 4 test circuits Instructor ____

Draw a Circuit with Two Switch External Switch and On-board Switch When complete dismantle switch box and put all components back into its box. Switch Light On Turn Light on 1 m 28 m 20 m 48 m Power + 12 Fuse Buzzer On Light Buzzer Pass out boxes, connect 4 test circuits Student work at own pace Instructor ____